how to repair a teapot that weeps through the craze

I had to look up what that was.
http://www.ebay.com/gds/A-Simple-Guide-to-the-Collectible-Teapot-/10000000000713001/g.html

Essentially, crazing seems to be hairline cracking in the glaze but not the pottery itself.

I am thinking that if it's 'weeping' (e. g. has slow leaks), you've got something deeper than crazing, and have actual cracks in the pottery. Gluing is probably not going to do you too much good, as most of it will soften in the heat of boiling or near-boiling water, not to mention the toxicity of many glues. What to do?

I'm sorry to say, but it's more likely that you should retire the piece to show status only, and use another teapot for serving tea.